Thermoform packaging machines of the type R535, produced by the applicant's firm are known. For producing a multilayer package comprising two product layers, these thermoform packaging machines can be equipped with separate work stations for cutting evacuation and gas flushing openings, and for circumferentially sealing evacuation and gas flushing openings so that both product layers can be evacuated and/or flushed with gas separately. The thermoform packaging machine can be extended by a work station for applying a corner cut.
Another thermoform packaging machine for producing a multilayer package is disclosed by DE 20 2005 015 901 U1. Here, a first product layer is fed in on a first film web, a second film web is supplied and positioned on top of the first product layer and a second product layer is placed onto the second film web. Together with an additional film web, the total group of three films comprising the two product layers therebetween is supplied to a sealing station. In so doing, the two product layers are evacuated and/or flushed with gas in common and subsequently the three film webs are all circumferentially sealed to one another so as to obtain a package with two separate product layers, and in a subsequent cutting station a separation step is executed. The second (central) film web is narrower than the first and third film webs so as not to cover the evacuation and gas flushing nozzles. This prior art is disadvantageous insofar as it is impossible to evacuate and/or flush with gas the different product layers precisely or differently.
A multilayer package with opening aids is disclosed in DE 20 2010 009 454 U1. Here, all the films are peelably sealed onto one another, and the package has opening aids on different corners so as to make the various product layers easily accessible. The films have different degrees of peelability so that the film for the upper product layer can be removed more easily than the middle film for the lower product layer. A packaging machine or a method of manufacturing such a multilayer package by means of a thermoform packaging machine is not referred to anywhere in this publication.